Efficacy of single-dose antibiotic against early-onset pneumonia in comatose patients who are ventilated

Ceftriaxone to prevent early ventilator-associated pneumonia in patients with acute brain injury: a multicentre, randomised, double-blind, placebo-controlled, assessor-masked superiority trial

BACKGROUND

Patients with acute brain injury are at high risk of ventilator-associated pneumonia (VAP). The benefit of short-term antibiotic prophylaxis remains debated. We aimed to establish the effect of an early, single dose of the antibiotic ceftriaxone on the incidence of early VAP in patients with severe brain injury who required mechanical ventilation.

METHODS

PROPHY-VAP was a multicentre, randomised, double-blind, placebo-controlled, assessor-masked, superiority trial conducted in nine intensive care units in eight French university hospitals. We randomly assigned comatose (Glasgow Coma Scale score [GCS] ≤12) adult patients (age ≥18 years) who required mechanical ventilation for at least 48 h after acute brain injury to receive intravenous ceftriaxone 2 g or placebo once within the 12 h following tracheal intubation. Participants did not receive selective oropharyngeal and digestive tract decontamination. The primary outcome was the proportion of patients developing early VAP from the 2nd to the 7th day of mechanical ventilation, confirmed by masked assessors. The analysis was reported in the modified intention-to-treat population, which comprised all randomly assigned patients except those who withdrew or did not give consent to continue and those who did not receive the allocated treatment because they met a criterion for non-eligibility. The trial is registered with ClinicalTrials.gov, NCT02265406.

FINDINGS

From Oct 14, 2015, to May 27, 2020, 345 patients were randomly assigned (1:1) to receive ceftriaxone (n=171) or placebo (n=174); 330 received the allocated intervention and 319 were included in the analysis (162 in the ceftriaxone group and 157 in the placebo group). 166 (52%) participants in the analysis were men and 153 (48%) were women. 15 patients did not receive the allocated intervention after randomisation and 11 withdrew their consent. Adjudication confirmed 93 cases of VAP, including 74 early infections. The incidence of early VAP was lower in the ceftriaxone group than in the placebo group (23 [14%] vs 51 [32%]; hazard ratio 0·60 [95% CI 0·38-0·95], p=0·030), with no microbiological impact and no adverse effects attributable to ceftriaxone.

INTERPRETATION

In patients with acute brain injury, a single ceftriaxone dose decreased the risk of early VAP. On the basis of our findings, we recommend that an early, single dose of ceftriaxone be included in all bundles for the prevention of VAP in patients with brain injury who require mechanical ventilation.

FUNDING

French Ministry of Social Affairs and Health.

Aspiration Pneumonia

Aspiration pneumonia is a lower respiratory tract infection that results from inhalation of foreign material, often gastric and oropharyngeal contents. It is important to distinguish this from a similar entity, aspiration with chemical pneumonitis, as treatment approaches may differ. An evolving understanding of the human microbiome has shed light on the pathogenesis of aspiration pneumonia, suggesting that dysbiosis, repetitive injury, and inflammatory responses play a role in its development. Risk factors for aspiration events involve a complex interplay of anatomical and physiological dysfunctions in the nervous, gastrointestinal, and pulmonary systems. Current treatment strategies have shifted away from anaerobic organisms as leading pathogens. Prevention of aspiration pneumonia primarily involves addressing oropharyngeal dysphagia, a significant risk factor for aspiration pneumonia, particularly among elderly individuals and those with cognitive and neurodegenerative disorders.

Ten Issues to Update in Nosocomial or Hospital-Acquired Pneumonia: An Expert Review

Nosocomial pneumonia, or hospital-acquired pneumonia (HAP), and ventilator-associated pneumonia (VAP) are important health problems worldwide, with both being associated with substantial morbidity and mortality. HAP is currently the main cause of death from nosocomial infection in critically ill patients. Although guidelines for the approach to this infection model are widely implemented in international health systems and clinical teams, information continually emerges that generates debate or requires updating in its management. This scientific manuscript, written by a multidisciplinary team of specialists, reviews the most important issues in the approach to this important infectious respiratory syndrome, and it updates various topics, such as a renewed etiological perspective for updating the use of new molecular platforms or imaging techniques, including the microbiological diagnostic stewardship in different clinical settings and using appropriate rapid techniques on invasive respiratory specimens. It also reviews both Intensive Care Unit admission criteria and those of clinical stability to discharge, as well as those of therapeutic failure and rescue treatment options. An update on antibiotic therapy in the context of bacterial multiresistance, in aerosol inhaled treatment options, oxygen therapy, or ventilatory support, is presented. It also analyzes the out-of-hospital management of nosocomial pneumonia requiring complete antibiotic therapy externally on an outpatient basis, as well as the main factors for readmission and an approach to management in the emergency department. Finally, the main strategies for prevention and prophylactic measures, many of them still controversial, on fragile and vulnerable hosts are reviewed.

Prophylactic antibiotics for preventing ventilator-associated pneumonia: a pairwise and Bayesian network meta-analysis

BACKGROUND

The role of prophylactic antibiotics in preventing ventilator-associated pneumonia (VAP) in patients undergoing invasive mechanical ventilation (IMV) remains unclear. This network meta-analysis compared the efficacy and safety of antibiotic prophylaxis in preventing VAP in an IMV population in intensive-care units (ICUs).

METHODS

We searched the PubMed, Web of Science, Embase, and Cochrane Library databases from inception to December 2021, to identify relevant studies assessing the impact of prophylactic antibiotics on the incidence of VAP, the mortality, and the duration of ICU stays and hospitalization to perform a meta-analysis.

RESULTS

Thirteen studies (2144 patients) were included, 12 of which were selected for the primary analysis, which revealed that treatment with prophylactic antibiotics resulted in a lower VAP rate compared with control groups [risk ratio (RR) = 0.62]. Bayesian network meta-analysis indicated that aerosolized tobramycin and intravenous ampicillin-sulbactam presented the greatest likelihood being the most efficient regimen for reducing VAP.

CONCLUSIONS

Antibiotic prophylaxis may reduce the incidence of VAP, but not the mortality, for adult patients undergoing IMV in ICUs. Tobramycin via nebulization and ampicillin-sulbactam via intravenous administration presented the greatest likelihood of being the most efficient regimen for preventing VAP. However, well-designed randomized studies are warranted before definite recommendations can be made.

Post-Stroke Infections: Insights from Big Data Using Clinical Data Warehouse (CDW)

This study analyzed a digitized database of electronic medical records (EMRs) to identify risk factors for post-stroke infections. The sample included 41,236 patients hospitalized with a first stroke diagnosis (ICD-10 codes I60, I61, I63, and I64) between January 2011 and December 2020. Logistic regression analysis was performed to examine the effect of clinical variables on post-stroke infection. Multivariable analysis revealed that post-stroke infection was associated with the male sex (odds ratio [OR]: 1.79; 95% confidence interval [CI]: 1.49-2.15), brain surgery (OR: 7.89; 95% CI: 6.27-9.92), mechanical ventilation (OR: 18.26; 95% CI: 8.49-44.32), enteral tube feeding (OR: 3.65; 95% CI: 2.98-4.47), and functional activity level (modified Barthel index: OR: 0.98; 95% CI: 0.98-0.98). In addition, exposure to steroids (OR: 2.22; 95% CI: 1.60-3.06) and acid-suppressant drugs (OR: 1.44; 95% CI: 1.15-1.81) increased the risk of infection. On the basis of the findings from this multicenter study, it is crucial to carefully evaluate the balance between the potential benefits of acid-suppressant drugs or corticosteroids and the increased risk of infection in patients at high risk for post-stroke infection.

Effects of systemic antibiotics in early onset ventilator-associated pneumonia in trauma patients: A single-centre retrospective cohort study

Background:

Ventilator-associated pneumonia is one of the commonest complications encountered in intubated patients: its incidence ranges from 20% to 60%, with higher incidences seen in patients with polytrauma. Ventilator-associated pneumonia can result in poor neurological outcomes upon discharge, longer duration of mechanical ventilation and prolonged intensive care unit stays. The use of systemic antibiotics has been proposed as one method to reduce this complication. However, its effectiveness remains to be determined, and concerns about bacterial resistance hinder its use. This study aims to evaluate the effects of systemic antibiotics on early ventilator-associated pneumonia prevention.

Methods:

This is a single-centred retrospective cohort study, using data in the local trauma registry from 2015 to 2020. Patients aged ⩾18 years who suffered from injury to the head or trunk and were intubated within 12 h of hospitalization were evaluated for early ventilator-associated pneumonia to determine the effectiveness of systemic antibiotics on the incidence of ventilator-associated pneumonia and to identify other risk factors for ventilator-associated pneumonia in patients suffering from trauma.

Result:

A total of 250 patients were recruited; 59 of them met the criteria for early onset ventilator-associated pneumonia. Early use of broad-spectrum antibiotics with potent anaerobic coverage was found to be protective for early onset ventilator-associated pneumonia (adjusted odds ratio = 0.228, p = 0.044). Increasing age and severe thoracic or abdominal injury were also found to be strong non-modifiable predictors for the development of early onset ventilator-associated pneumonia.

Conclusion:

Use of systemic antibiotics with potent anaerobic coverage within 3 h of injury was found to prevent early onset ventilator-associated pneumonia in those intubated within 12 h of injury. However, a large-scale randomized control trial may be needed to further evaluate its benefit and its potential side effects, most notably the risk of antibiotic resistance.

Risk factors and outcomes associated with ventilator associated pneumonia amongst intubated trauma patients admitted to the general intensive care unit of a major trauma centre

Background

Despite the use of care bundles, ventilator associated pneumonia (VAP) remains a frequently occurring health care-associated infection, increasing costs, length of stay (LOS) and mortality. The incidence is higher amongst trauma patients, although due to variable definitions and study populations risk factors for developing VAP are disputed, with few reports from the UK.

Methods

This 6-year review of intubated trauma patients admitted to the general Intensive Care Unit (ICU) of a UK major trauma centre, collected data on suspected risk factors for VAP, as well as demographic information, outcomes and microbiology. Ninety-nine patients who developed VAP within the first 7 days of admission were compared with 191 patient who did not, with multivariable logistic regression used to control for confounding variables.

Results

Univariable analysis suggested that injury severity score (ISS) (34 v 29), head injury (66.7% v 50.8%), polytrauma (79.8% v 68.1%) and ventilator days (10 v 5) were associated with increased risk of VAP, but after adjustment only ventilator days remained significant (OR 1.04, 95% CI 1.01–1.06). Antibiotics within 24 h of admission were associated with reduced odds of developing VAP, whether this was for pulmonary prophylaxis (OR 0.43, 95% CI 0.22–0.83, p = 0.013) or non-pulmonary reasons (OR 0.27, 95% CI 0.15–0.51, p < 0.001).

Conclusions

Only increasing ventilator days was associated with increased odds of developing VAP. The use of early antimicrobials was associated strongly with a reduction in the odds of developing VAP; this could be explained by unmeasured confounding or a prophylactic effect against aspiration.

Ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arresT (PROTECT): study protocol for a randomized, placebo-controlled trial

BACKGROUND

Pneumonia is the most common infection after out-of-hospital cardiac arrest (OHCA) occurring in up to 65% of patients who remain comatose after return of spontaneous circulation. Preventing infection after OHCA may (1) reduce exposure to broad-spectrum antibiotics, (2) prevent hemodynamic derangements due to local and systemic inflammation, and (3) prevent infection-associated morbidity and mortality.

METHODS

The ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arrest (PROTECT) trial is a randomized, placebo-controlled, single-center, quadruple-blind (patient, treatment team, research team, outcome assessors), non-commercial, superiority trial to be conducted at Maine Medical Center in Portland, Maine, USA. Ceftriaxone 2 g intravenously every 12 h for 3 days will be compared with matching placebo. The primary efficacy outcome is incidence of early-onset pneumonia occurring < 4 days after mechanical ventilation initiation. Concurrently, T cell-mediated inflammation bacterial resistomes will be examined. Safety outcomes include incidence of type-one immediate-type hypersensitivity reactions, gallbladder injury, and Clostridioides difficile-associated diarrhea. The trial will enroll 120 subjects over approximately 3 to 4 years.

DISCUSSION

The PROTECT trial is novel in its (1) inclusion of OHCA survivors regardless of initial heart rhythm, (2) use of a low-risk antibiotic available in the USA that has not previously been tested after OHCA, (3) inclusion of anti-inflammatory effects of ceftriaxone as a novel mechanism for improved clinical outcomes, and (4) complete metagenomic assessment of bacterial resistomes pre- and post-ceftriaxone prophylaxis. The long-term goal is to develop a definitive phase III trial powered for mortality or functional outcome.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04999592 . Registered on August 10, 2021.

Analysis of risk factors for early-onset ventilator-associated pneumonia in a neurosurgical intensive care unit

Background

Ventilator-associated pneumonia (VAP) is a severe infection among patients in the neurosurgery intensive care unit (NICU).

Methods

We retrospectively evaluated risk factors for early-onset ventilator-associated pneumonia (EOVAP) from January 2019 to December 2019 at a NICU. A total of 89 NICU patients who were intubated within 48 h of onset and whose mechanical ventilation time was at least 7 days were enrolled. We evaluated EOVAP that occurred within the first 7 days after the onset of mechanical ventilation. The enrolled patients had no history of chronic lung disease and no clinical manifestations of infection before intubation. Clinical data of patients were recorded, and the incidence of and risk factors for EOVAP were analyzed. Patients were also grouped by age (≥ 65 vs. < 65 years) and whether they had received hypothermia treatment or not.

Results

Among 89 mechanically ventilated patients (49 men and 40 women; the mean age ± SD was 60.1 ± 14.3 years), 40 patients (44.9%) developed EOVAP within 7 days and 14 patients (15.7%) had a multidrug resistant bacterial infection. Binary logistic regression analysis indicated that older age (≥ 65 years) (odds ratio [OR]:3.53, 95% confidence interval [CI]:1.27–9.79, P = 0.015) and therapeutic hypothermia (OR:3.68, CI:1.10–12.31, p = 0.034) were independent predictors of EOVAP. Levels of peripheral blood leukocytes, neutrophils and platelets were lower in the therapeutic hypothermia group than those who did not receive hypothermia treatment.

Conclusions

This study found that older age (≥ 65 years) and therapeutic hypothermia were independently associated with the risk of EOVAP in NICU patients.

Impact on antimicrobial consumption of procalcitonin-guided antibiotic therapy for pneumonia/pneumonitis associated with aspiration in comatose mechanically ventilated patients: a multicenter, randomized controlled study

Background

In comatose patients receiving oro-tracheal intubation for mechanical ventilation (MV), the risk of aspiration is increased. Aspiration can lead to chemical pneumonitis (inflammatory reaction to the gastric contents), or aspiration pneumonia (infection caused by inhalation of microorganisms). Distinguishing between the two types is challenging. We tested the interest of using a decisional algorithm based on procalcitonin (PCT) values to guide initiation and discontinuation of antibiotic therapies in intubated patients.

Methods

The PROPASPI (PROcalcitonin Pneumonia/pneumonitis Associated with ASPIration) trial is a multicenter, prospective, randomized, controlled, single-blind, superiority study comparing two strategies: (1) an intervention group where threshold PCT values were used to guide initiation and discontinuation of antibiotics (PCT group); and (2) a control group, where antibiotic therapy was managed at the physician’s discretion. Patients aged 18 years or over, intubated for coma (Glasgow score ≤ 8), with MV initiated within 48 h after admission, were eligible. The primary endpoint was the duration of antibiotic treatment during the first 15 days after admission to the ICU.

Results

From 24/2/2015 to 28/8/2019, 1712 patients were intubated for coma in the 5 participating centers, of whom 166 were included in the study. Data from 159 were available for intention-to-treat analysis: 81 in the PCT group, and 78 in the control group. Overall, 67 patients (43%) received antibiotics in the intensive care unit (ICU); there was no significant difference between groups (37 (46%) vs 30 (40%) for PCT vs control, p = 0.432). The mean duration of antibiotic treatment during the first 15 days in the ICU was 2.7 ± 3.8 days; there was no significant difference between groups (3.0 ± 4.1 days vs 2.3 ± 3.4 days for PCT vs control, p = 0.311). The mean number of days under MV was significantly higher in the PCT group (3.7 ± 3.6 days) than in controls (2.7 ± 2.5 days, p = 0.033). The duration of ICU stay was also significantly longer in the PCT group: 6.4 ± 6.5 days vs 4.6 ± 3.5 days in the control group (p = 0.043). After adjustment for SAPS II score, the difference in length of stay and duration of mechanical ventilation between groups was no longer significant.

Conclusion

The use of PCT values to guide therapy, in comparison to the use of clinical, biological (apart from PCT) and radiological criteria, does not modify exposure to antibiotics in patients intubated for coma.

Trial registration Clinicaltrials.gov Identifier NCT02862314.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00931-4.

Bacterial Pneumonia in Brain-Dead Patients: Clinical Features and Impact on Lung Suitability for Donation

OBJECTIVES

To appraise the epidemiological features of bacterial pneumonia and its impact on lung suitability for donation in brain-dead patients managed with protective ventilatory settings.

DESIGN

Retrospective observational study.

SETTING

Six ICUs from two university-affiliated hospitals.

PATIENTS

Brain-dead adult patients managed in the participating ICUs over a 4-year period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among the 231 included patients, 145 (62.8%) were classified as ideal or extended-criteria potential lung donors at ICU admission and the remaining 86 patients having baseline contraindication for donation. Culture-proven aspiration pneumonia and early-onset ventilator-associated pneumonia occurred in 54 patients (23.4%) and 15 patients (6.5%), respectively (overall pneumonia incidence, 29.9%). Staphylococcus aureus and Enterobacterales were the most common pathogens. Using mixed-effects Cox proportional hazard models, age (adjusted hazard ratio, 0.98; 95% CI [0.96-0.99]), anoxic brain injury (3.55 [1.2-10.5]), aspiration (2.29 [1.22-4.29]), and not receiving antimicrobial agents at day 1 (3.56 [1.94-6.53]) were identified as independent predictors of pneumonia occurrence in the whole study population. Analyses restricted to potential lung donors yielded similar results. Pneumonia was associated with a postadmission decrease in the PaO2/FIO2 ratio and lower values at brain death, in the whole study population (estimated marginal mean, 294 [264-323] vs 365 [346-385] mm Hg in uninfected patients; p = 0.0005) as in potential lung donors (299 [248-350] vs 379 [350-408] mm Hg; p = 0.04; linear mixed models). Lungs were eventually retrieved in 31 patients (34.4%) among the 90 potential lung donors with at least one other organ harvested (pneumonia prevalence in lung donors (9.7%) vs nondonors (49.2%); p = 0.0002).

CONCLUSIONS

Pneumonia occurs in one-third of brain-dead patients and appears as the main reason for lung nonharvesting in those presenting as potential lung donors. The initiation of antimicrobial prophylaxis upon the first day of the ICU stay in comatose patients with severe brain injury could enlarge the pool of actual lung donors.

Blunt and Penetrating Severe Traumatic Brain Injury

Severe traumatic brain injury is a common problem. Current practices focus on the importance of early resuscitation, transfer to high-volume centers, and provider expertise across multiple specialties. In the emergency department, patients should receive urgent intracranial imaging and consideration for tranexamic acid. Close observation in the intensive care unit environment helps identify problems, such as seizure, intracranial pressure crisis, and injury progression. In addition to traditional neurologic examination, patients benefit from use of intracranial monitors. Monitors gather physiologic data on intracranial and cerebral perfusion pressures to help guide therapy. Brain tissue oxygenation monitoring and cerebromicrodialysis show promise in studies.

Prevention of Early Ventilator-Associated Pneumonia after Cardiac Arrest

BACKGROUND

Patients who are treated with targeted temperature management after out-of-hospital cardiac arrest with shockable rhythm are at increased risk for ventilator-associated pneumonia. The benefit of preventive short-term antibiotic therapy has not been shown.

METHODS

We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving adult patients (>18 years of age) in intensive care units (ICUs) who were being mechanically ventilated after out-of-hospital cardiac arrest related to initial shockable rhythm and treated with targeted temperature management at 32 to 34°C. Patients with ongoing antibiotic therapy, chronic colonization with multidrug-resistant bacteria, or moribund status were excluded. Either intravenous amoxicillin-clavulanate (at doses of 1 g and 200 mg, respectively) or placebo was administered three times a day for 2 days, starting less than 6 hours after the cardiac arrest. The primary outcome was early ventilator-associated pneumonia (during the first 7 days of hospitalization). An independent adjudication committee determined diagnoses of ventilator-associated pneumonia.

RESULTS

A total of 198 patients underwent randomization, and 194 were included in the analysis. After adjudication, 60 cases of ventilator-associated pneumonia were confirmed, including 51 of early ventilator-associated pneumonia. The incidence of early ventilator-associated pneumonia was lower with antibiotic prophylaxis than with placebo (19 patients [19%] vs. 32 [34%]; hazard ratio, 0.53; 95% confidence interval, 0.31 to 0.92; P = 0.03). No significant differences between the antibiotic group and the control group were observed with respect to the incidence of late ventilator-associated pneumonia (4% and 5%, respectively), the number of ventilator-free days (21 days and 19 days), ICU length of stay (5 days and 8 days if patients were discharged and 7 days and 7 days if patients had died), and mortality at day 28 (41% and 37%). At day 7, no increase in resistant bacteria was identified. Serious adverse events did not differ significantly between the two groups.

CONCLUSIONS

A 2-day course of antibiotic therapy with amoxicillin-clavulanate in patients receiving a 32-to-34°C targeted temperature management strategy after out-of-hospital cardiac arrest with initial shockable rhythm resulted in a lower incidence of early ventilator-associated pneumonia than placebo. No significant between-group differences were observed for other key clinical variables, such as ventilator-free days and mortality at day 28. (Funded by the French Ministry of Health; ANTHARTIC ClinicalTrials.gov number, NCT02186951.).

Influence of Single-Dose Antibiotic Prophylaxis for Early-Onset Pneumonia in High-Risk Intubated Patients

BACKGROUND

Early-onset pneumonia (EOP) after endotracheal intubation is common among critically ill patients with a neurologic injury and is associated with worse clinical outcomes.

METHODS

This retrospective cohort study observed outcomes pre- and post-implementation of an EOP prophylaxis protocol which involved the administration of a single dose of ceftriaxone 2 g around the time of intubation. The study included patients ≥ 18 years who were admitted to the University of North Carolina Medical Center (UNCMC) neuroscience intensive care unit (NSICU) between April 1, 2014, and October 26, 2016, and intubated for ≥ 72 h.

RESULTS

Among the 172 patients included, use of an EOP prophylaxis protocol resulted in a significant reduction in the rate of microbiologically confirmed EOP compared to those without prophylaxis (7.4 vs 19.8%, p = 0.026). However, EOP prophylaxis did not decrease the combined incidence of microbiologically confirmed or clinically suspected EOP (32.2 vs 37.4%, p = 0.523). No difference in the rate of late-onset pneumonia (34.6 vs 26.4%, p = 0.25) or virulent organism growth (19.8 vs 14.3%, p = 0.416) was observed. No difference was observed in the duration of intubation, duration of intensive care unit (ICU) stay, duration of hospitalization, or ICU antibiotic days within 30 days of intubation. In hospital mortality was found to be higher in those who received EOP prophylaxis compared to those who did not receive prophylaxis (45.7 vs 29.7%, p = 0.04).

CONCLUSIONS

The administration of a single antibiotic dose following intubation may reduce the incidence of microbiologically confirmed EOP in patients with neurologic injury who are intubated ≥ 72 h. A prophylaxis strategy does not appear to increase the rate of virulent organism growth or the rate of late-onset pneumonia. However, this practice is not associated with a decrease in days of antibiotic use in the ICU or any clinical outcomes benefit.

Infection Prevention in the Neurointensive Care Unit: A Systematic Review

Hospital-acquired infections are common in neurointensive care units. We sought to review interventions which may reduce infection rates in neurocritically ill populations. We conducted a systematic review of studies targeting adult patients in neuro-intensive care units (neuro-ICUs) with an intervention designed to prevent ICU-acquired infections. Our outcome of interest was change in the prevalence or rates of infection between active and control arms of these studies. We excluded studies based on the following criteria: no English full-text version available; pediatric population; non-neurosciences ICU population; pre- or intraoperative methods to prevent infection; lack of discrete data for infection rates/prevalence; studies that were purely observational in nature and did not test an intervention; and studies performed in resource limited settings. We initially retrieved 3716 results by searching the following databases: PubMed/MEDLINE, EMBASE via Ovid, and Cochrane CENTRAL via Ovid. No date or language limits were used in the search. Computerized deduplication was conducted using EndNote followed by a confirmatory manual review resulting in 3414 citations. An additional 19 manuscripts were identified through review of references. The screening process followed a standard protocol, using two screeners at the title/abstract level to determine relevance and at the full-text level to determine eligibility for inclusion. The 3427 titles/abstracts were independently screened by two board-certified neurointensivists to determine relevance for full-text review, and 3248 were rejected. The remaining 179 abstracts were reviewed in full text using predetermined inclusion/exclusion criteria. Ultimately, 75 articles met our inclusion criteria and were utilized in the final analysis. The reviewed literature highlights the need for collaborative, multi-disciplinary, and multi-pronged approaches to reduce infections. Rates of VRI, SSI, VAP, CAUTI, and CLABSI can approach zero with persistence and a team-based approach.

Prophylactic antibiotic use following cardiac arrest: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of prophylactic/ early antibiotics (intervention group) compared with clinically driven/ delayed antibiotics (control group) on patient and infectious outcomes in adult cardiac arrest patients admitted to hospital.

DATA SOURCES

We searched MEDLINE (1946-current), EMBASE (1947-current) and the Cochrane library (inception-current) on 8th May 2018. Additional citations were identified through forward and backward citation tracking.

STUDY SELECTION

Two reviewers independently screened titles, abstracts, and full-texts. We included observational and interventional primary research studies with a concurrent or retrospective control group that were relevant to our study objective.

DATA EXTRACTION

We extracted data using a piloted data extraction form. Risk of bias was assessed using the Cochrane tool for randomised controlled trials or the GRADE tool for risk of bias in observational studies. Overall evidence quality for each outcome was assessed using the GRADE system.

DATA SYNTHESIS

Databases searches and citation tracking identified 6825 citations, of which ten citations containing 11 studies (3 randomised controlled trials, 8 observational studies) were eligible for inclusion. Data were summarised in meta-analyses using random-effect models. The intervention was not associated with increased survival (odds ratio 1.16, 95% CI 0.97-1.40), survival with good neurological outcome (odds ratio 2.25, 95% CI 0.93-5.45), critical care length of stay (mean difference -0.6, 95% CI -3.6 to 2.4) or incidence of pneumonia (odds ratio 0.58, 95% CI 0.23-1.46). Findings were generally consistent between observational studies and randomised controlled trials.

CONCLUSIONS

Antibiotic prophylaxis following cardiac arrest is not associated with a change in key clinical outcomes. Further high-quality trials may be needed to address this important clinical question. Review registration: PROSPERO CRD42016039358.

Prevention of early ventilation-acquired pneumonia (VAP) in comatose brain-injured patients by a single dose of ceftriaxone: PROPHY-VAP study protocol, a multicentre, randomised, double-blind, placebo-controlled trial

INTRODUCTION

Ventilator-associated pneumonia (VAP) is the first cause of healthcare-associated infections in intensive care units (ICUs) and brain injury is one of the main risk factors for early-onset VAP. Antibiotic prophylaxis has been reported to decrease their occurrence in brain-injured patients, but a lack of controlled randomised trials and the risk of induction of bacterial resistance explain the low level of recommendations. The goal of this study is to determine whether a single dose of ceftriaxone within the 12 hours postintubation after severe brain injury can decrease the risk of early-onset VAP.

METHODS AND ANALYSIS

The PROPHY-VAP is a French multicentre, randomised, double-blind, placebo-controlled, clinical trial. Adult brain-injured patients (n=320) with a Glasgow Coma Scale ≤12, requiring mechanical ventilation for more than 48 hours, are randomised to receive either a single dose of ceftriaxone 2 g or a placebo within the 12 hours after tracheal intubation. The primary endpoint is the proportion of patients developing VAP from the 2nd to the 7th day after mechanical ventilation. Secondary endpoints include the proportion of patients developing late VAP (>7 days after tracheal intubation), the number of ventilator-free days, VAP-free days and antibiotic-free days, length of stay in the ICU, proportion of patients with ventilator-associated events and mortality during their ICU stay.

ETHICS AND DISSEMINATION

The initial research project was approved by the Institutional Review Board of OUEST III (France) on 20 October 2014 (registration No 2014-001668-36) and carried out according to the principles of the Declaration of Helsinki and the Clinical Trials Directive 2001/20/EC of the European Parliament relating to the Good Clinical Practice guidelines. The results of this study will be presented in national and international meetings and published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT02265406; Pre-results.

Efficacy of antibiotic prophylaxis against ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is one of the most important problems of intensive care units. Eighty-four neurologic patients with acute stroke (Glasgow Coma Score ≤8) were entered into a double-blind clinical trial. Patients in the intervention group received piperacillin-tazobactam 4 g/0.5 g at the time of intubation and 12 h later. The incidences of early-onset (within four days of intubation) and late-onset VAP were 9.2 and 26.9 episodes per 1000 days of mechanical ventilation in the intervention and control groups, respectively (odds ratio: 0.217; 95% confidence interval: 0.056-0.085; P = 0.028). Administration of prophylactic piperacillin-tazobactam may reduce early-onset VAP, but the benefit does not extend to late-onset VAP.

Impact of immunosuppression on incidence, aetiology and outcome of ventilator-associated lower respiratory tract infections

The aim of this planned analysis of the prospective multinational TAVeM database was to determine the incidence, aetiology and impact on outcome of ventilator-associated lower respiratory tract infections (VA-LRTI) in immunocompromised patients.All patients receiving mechanical ventilation for >48 h were included. Immunocompromised patients (n=663) were compared with non-immunocompromised patients (n=2297).The incidence of VA-LRTI was significantly lower among immunocompromised than among non-immunocompromised patients (16.6% versus 24.2%; sub-hazard ratio 0.65, 95% CI 0.53-0.80; p<0.0001). Similar results were found regarding ventilator-associated tracheobronchitis (7.3% versus 11.6%; sub-hazard ratio 0.61, 95% CI 0.45-0.84; p=0.002) and ventilator-associated pneumonia (9.3% versus 12.7%; sub-hazard ratio 0.72, 95% CI 0.54-0.95; p=0.019). Among patients with VA-LRTI, the rates of multidrug-resistant bacteria (72% versus 59%; p=0.011) and intensive care unit mortality were significantly higher among immunocompromised than among non-immunocompromised patients (54% versus 30%; OR 2.68, 95% CI 1.78-4.02; p<0.0001). In patients with ventilator-associated pneumonia, mortality rates were higher among immunocompromised than among non-immunocompromised patients (64% versus 34%; p<0.001).Incidence of VA-LRTI was significantly lower among immunocompromised patients, but it was associated with a significantly higher mortality rate. Multidrug-resistant pathogens were more frequently found in immunocompromised patients with VA-LRTI.

Respective impact of implementation of prevention strategies, colonization with multiresistant bacteria and antimicrobial use on the risk of early- and late-onset VAP: An analysis of the OUTCOMEREA network

Rationale

The impact of prevention strategies and risk factors for early-onset (EOP) versus late-onset (LOP) ventilator-associated pneumonia (VAP) are still debated.

Objectives

To evaluate, in a multicenter cohort, the risk factors for EOP and LOP, as the evolution of prevention strategies.

Methods

7,784 patients with mechanical ventilation (MV) for at least 48 hours were selected into the multicenter prospective OUTCOMEREA database (1997–2016). VAP occurring between the 3^rd and 6^th day of MV defined EOP, while those occurring after defined LOPs. We used a Fine and Gray subdistribution model to take the successful extubation into account as a competing event.

Measurements and main results

Overall, 1,234 included patients developed VAP (EOP: 445 (36%); LOP: 789 (64%)). Male gender was a risk factor for both EOP and LOP. Factors specifically associated with EOP were admission for respiratory distress, previous colonization with multidrug-resistant Pseudomonas aeruginosa, chest tube and enteral feeding within the first 2 days of MV. Antimicrobials administrated within the first 2 days of MV were all protective of EOP. ICU admission for COPD exacerbation or pneumonia were early risk factors for LOP, while imidazole and vancomycin use within the first 2 days of MV were protective factors. Late risk factors (between the 3^rd and the 6^th day of MV) were the intra-hospital transport, PAO2-FIO2<200 mmHg, vasopressor use, and known colonization with methicillin-resistant Staphylococcus aureus. Among the antimicrobials administered between the 3^rd and the 6^th day, fluoroquinolones were the solely protective one.Contrarily to LOP, the risk of EOP decreased across the study time periods, concomitantly with an increase in the compliance with bundle of prevention measures.

Conclusion

VAP risk factors are mostly different according to the pneumonia time of onset, which should lead to differentiated prevention strategies.

Clinical and social barriers to antimicrobial stewardship in pulmonary medicine: A qualitative study

BACKGROUND

The treatment of pulmonary infections is one of the largest indications for antibiotics in human health care, offering significant potential for antibiotic optimization internationally. This study explores the perspectives of pulmonary clinicians on antibiotic use in hospital pulmonary infections.

METHODS

Twenty-eight pulmonary doctors and nurses from 2 hospitals participated in semi-structured interviews focusing on their experiences of antibiotic use.

RESULTS

Barriers to antibiotic optimization in pulmonary infections were identified. Clinical barriers are as follows. The first is differentiating pneumonia vs chronic obstructive pulmonary disease: differentiating pulmonary diagnoses was reported as challenging, leading to overtreatment. The second is differentiating viral vs bacterial: diagnostic differentiation was perceived to contribute to excess antibiotic use. The third is differentiating colonization vs pathogen: the interpretation of ambiguous results was reported to lead to under- or overprescribing depending on the perspective of the treating team. Social barriers are as follows. The first is the perception of resistance: antibiotic resistance was not perceived as an immediate threat. The second is the perceived value of antibiotic clinical guidelines: there was mistrust in antibiotic guidelines. The third is hospital hierarchies: hierarchical structures had a significant influence on prescribing.

CONCLUSIONS

Substantial barriers to antibiotic optimization in pulmonary infections were identified. To facilitate change in antibiotic use there must be a systematic understanding and interventions to address specific clinical issues. In the case of pulmonary medicine, significant identified issues, such as mistrust in clinical guidelines and diagnostic challenges, need to be addressed.

Systemic antibiotics for preventing ventilator-associated pneumonia in comatose patients: a systematic review and meta-analysis

BACKGROUND

Early-onset ventilator-associated pneumonia (EO-VAP) is the leading cause of morbidity and mortality in comatose patients. However, VAP prevention bundles focus mainly on late-onset VAP and may be less effective in preventing EO-VAP in comatose patients. Systemic antibiotic administration at the time of intubation may have a role in preventing EO-VAP. Therefore, we evaluated the effectiveness of systemic antibiotic administration in VAP prevention in comatose patients through a systematic review and meta-analysis.

METHODS

We searched for studies published through December 2015 that evaluated systemic antibiotic prophylaxis in comatose patients. Two authors independently selected and evaluated full-length reports of randomized clinical trials or prospective cohorts in patients aged >16 years that evaluated the impact of systemic antibiotics at the time of intubation on EO-VAP compared to placebo or no prophylaxis. The outcome variables were the incidence of EO-VAP, the duration of mechanical ventilation, ICU length of stay, and ICU mortality.

RESULTS

We identified 10,988 citations, yielding 26 articles for further analysis; three studies with 267 patients were finally analyzed. Most patients (n = 135) were comatose due to head trauma. Systemic antibiotic administration was associated with decreased incidence of EO-VAP (RR 0.32; 95% CI 0.19-0.54) and shorter ICU LOS (standardized mean difference -0.32; 95% CI -0.56 to -0.08), but had no effect on mortality (RR 1.03; 95% CI 0.7-1.53) or duration of mechanical ventilation (standardized mean difference -0.16; 95% CI -0.41 to 0.08).

CONCLUSIONS

Antibiotic prophylaxis in comatose patients reduced the incidence of EO-VAP and decreased the ICU stay slightly. Future trials are needed to confirm these results.

Advances in antibiotic therapy in the critically ill

Infections occur frequently in critically ill patients and their management can be challenging for various reasons, including delayed diagnosis, difficulties identifying causative microorganisms, and the high prevalence of antibiotic-resistant strains. In this review, we briefly discuss the importance of early infection diagnosis, before considering in more detail some of the key issues related to antibiotic management in these patients, including controversies surrounding use of combination or monotherapy, duration of therapy, and de-escalation. Antibiotic pharmacodynamics and pharmacokinetics, notably volumes of distribution and clearance, can be altered by critical illness and can influence dosing regimens. Dosing decisions in different subgroups of patients, e.g., the obese, are also covered. We also briefly consider ventilator-associated pneumonia and the role of inhaled antibiotics. Finally, we mention antibiotics that are currently being developed and show promise for the future.

The association between age, sex, and hospital-acquired infection rates: results from the 2009-2011 National Medicare Patient Safety Monitoring System

OBJECTIVE

To define the relationships between age, sex and hospital-acquired infection (HAI) rates in a national cohort of hospitalized patients.

METHODS

Analysis of chart-abstracted Medicare Patient Safety Monitoring System data from randomly selected medical records of patients hospitalized between January 1, 2009, and December 31, 2011, for acute cardiovascular disease, pneumonia, or major surgery associated with 1 of 6 HAIs. Patients were stratified into 6 groups. We then analyzed the association of age, sex, and 2 outcomes; the rate of occurrence of HAI for patients who were at risk and the rate of patients having at least 1 HAI.

RESULTS

Among 85,461 patients, all groups except younger female surgical patients had higher catheter-associated urinary tract infection (CAUTI) rates than male patients. After adjustment for comorbidities, there was no overall evidence of higher HAI rates among elderly patients. In patients with acute cardiovascular disease, women had higher rates of HAIs. Among patients with pneumonia, there was no significant difference in the rate of HAIs among most age and sex groups. Among surgical patients, all age and sex groups had a significantly higher adjusted rate of developing at least 1 HAI except females 65 years of age or older. Similar results were seen for the outcome of the occurrence rate of HAIs.

CONCLUSIONS

There was not an overall increased risk of HAIs among older patients hospitalized for acute cardiovascular disease, pneumonia, and major surgery after adjustment for comorbidities. The relationship between sex and the rate of HAIs varied depending upon the underlying acute reason for hospitalization.

Incidence and prognosis of ventilator-associated tracheobronchitis (TAVeM): a multicentre, prospective, observational study

BACKGROUND

Ventilator-associated tracheobronchitis has been suggested as an intermediate process between tracheobronchial colonisation and ventilator-associated pneumonia in patients receiving mechanical ventilation. We aimed to establish the incidence and effect of ventilator-associated tracheobronchitis in a large, international patient cohort.

METHODS

We did a multicentre, prospective, observational study in 114 intensive care units (ICU) in Spain, France, Portugal, Brazil, Argentina, Ecuador, Bolivia, and Colombia over a preplanned time of 10 months. All patients older than 18 years admitted to an ICU who received invasive mechanical ventilation for more than 48 h were eligible. We prospectively obtained data for incidence of ventilator-associated lower respiratory tract infections, defined as ventilator-associated tracheobronchitis or ventilator-associated pneumonia. We grouped patients according to the presence or absence of such infections, and obtained data for the effect of appropriate antibiotics on progression of tracheobronchitis to pneumonia. Patients were followed up until death or discharge from hospital. To account for centre effects with a binary outcome, we fitted a generalised estimating equation model with a logit link, exchangeable correlation structure, and non-robust standard errors. This trial is registered with ClinicalTrials.gov, number NCT01791530.

FINDINGS

Between Sept 1, 2013, and July 31, 2014, we obtained data for 2960 eligible patients, of whom 689 (23%) developed ventilator-associated lower respiratory tract infections. The incidence of ventilator-associated tracheobronchitis and that of ventilator-associated pneumonia at baseline were similar (320 [11%; 10·2 of 1000 mechanically ventilated days] vs 369 [12%; 8·8 of 1000 mechanically ventilated days], p=0·48). Of the 320 patients with tracheobronchitis, 250 received appropriate antibiotic treatment and 70 received inappropriate antibiotics. 39 patients with tracheobronchitis progressed to pneumonia; however, the use of appropriate antibiotic therapy for tracheobronchitis was associated with significantly lower progression to pneumonia than was inappropriate treatment (19 [8%] of 250 vs 20 [29%] of 70, p<0·0001; crude odds ratio 0·21 [95% CI 0·11-0·41]). Significantly more patients with ventilator-associated pneumonia died (146 [40%] of 369) than those with tracheobronchitis (93 [29%] of 320) or absence of ventilator-associated lower respiratory tract infections (673 [30%] of 2271, p<0·0001). Median time to discharge from the ICU for survivors was significantly longer in the tracheobronchitis (21 days [IQR 15-34]) and pneumonia (22 [13-36]) groups than in the group with no ventilator-associated lower respiratory tract infections (12 [8-20]; hazard ratio 1·65 [95% CI 1·38-1·97], p<0·0001).

INTERPRETATION

This large database study emphasises that ventilator-associated tracheobronchitis is a major health problem worldwide, associated with high resources consumption in all countries. Our findings also show improved outcomes with use of appropriate antibiotic treatment for both ventilator-associated tracheobronchitis and ventilator-associated pneumonia, underlining the importance of treating both infections, since inappropriate treatment of tracheobronchitis was associated with a higher risk of progression to pneumonia.

FUNDING

None.

Major publications in the critical care pharmacotherapy literature: January-December 2013

PURPOSE

Ten recently published articles with important implications for critical care pharmacotherapy are summarized.

SUMMARY

The Critical Care Pharmacotherapy Literature Update (CCPLU) group is a national assembly of experienced intensive care unit (ICU) pharmacists across the United States. Group members monitor 25 peer-reviewed journals on an ongoing basis to identify literature relevant to pharmacy practice in the critical care setting. After evaluation by CCPLU group members, selected articles are chosen for summarization and distribution to group members nationwide based on (1) applicability to critical care practice, (2) relevance to pharmacy practitioners, and (3) quality of evidence or research methodology. Hundreds of relevant articles were evaluated by the group during the period January-December 2013, of which 98 were summarized and disseminated nationally to CCPLU group members. Among those 98 publications, 10 deemed to be of particularly high utility to critical care practitioners were included in this review. The 10 articles address topics such as rapid lowering of blood pressure in patients with intracranial hemorrhage, adjunctive therapy to prevent renal injury due to acute heart failure, triple-drug therapy to improve neurologic outcomes after cardiac arrest, and continuous versus intermittent infusion of β-lactam antibiotics in severe sepsis.

CONCLUSION

There were many important additions to the critical care pharmacotherapy literature in 2013, including an updated guideline on the management of myocardial infarction and reports on advances in research focused on improving outcomes in patients with stroke or cardiac arrest and preventing the spread of drug-resistant pathogens in the ICU.

Prehospital oral chlorhexidine does not reduce the rate of ventilator-associated pneumonia among critically ill trauma patients: A prospective concurrent-control study

PURPOSE

The purpose of the study was to test the hypothesis that prehospital oral chlorhexidine administered to intubated trauma patients will decrease the Clinical Pulmonary Infection Score (CPIS) during the first 2 days of hospitalization.

MATERIALS AND METHODS

Prospective interventional concurrent-control study of all intubated adult trauma patients transported by air ambulance to a 711-bed Midwestern academic trauma center over a 1-year period. Patients transported by 2 university-based helicopters were treated with oral chlorhexidine after intubation, and the control group was patients transported by other air transport services.

RESULTS

Sixty-seven patients were enrolled, of which 23 received chlorhexidine (9 patients allocated to the intervention were not treated). The change in CPIS score was no different between the intervention and control groups by intention to treat (1.06- vs 1.40-point reduction, P = .520), and no difference was observed in tracheal colonization (29.0% vs 36.7%, P = .586). No differences were observed in the rate of clinical pneumonia (8.7% vs 8.6%, P = .987) or mortality (P = .196) in the per-protocol chlorhexidine group.

CONCLUSIONS

The prehospital administration of oral chlorhexidine does not reduce the CPIS score over the first 48 hours of admission for intubated trauma patients. Further study should explore other prehospital strategies of reducing complications of critical illness.

Systematic review of the literature and evidence-based recommendations for antibiotic prophylaxis in trauma: results from an Italian consensus of experts

BACKGROUND

Antibiotic prophylaxis is frequently administered in severe trauma. However, the risk of selecting resistant bacteria, a major issue especially in critical care environments, has not been sufficiently investigated. The aim of the present study was to provide guidelines for antibiotic prophylaxis for four different trauma-related clinical conditions, taking into account the risks of antibiotic-resistant bacteria selection, thus innovating previous guidelines in the field.

METHODS

The MEDLINE database was searched for studies comparing antibiotic prophylaxis to controls (placebo or no antibiotic administration) in four clinical traumatic conditions that were selected on the basis of the traumatic event frequency and/or infection severity. The selected studies focused on the prevention of early ventilator associated pneumonia (VAP) in comatose patients with traumatic brain injury, of meningitis in severe basilar skull fractures, of wound infections in long-bone open fractures. Since no placebo-controlled study was available for deep surgical site-infections prevention in abdominal trauma with enteric contamination, we compared 24-hour and 5-day antibiotic prophylaxis policies. A separate specific research focused on the question of antibiotic-resistant bacteria selection caused by antibiotic prophylaxis, an issue not adequately investigated by the selected studies. Randomised trials, reviews, meta-analyses, observational studies were included. Data extraction was carried out by one author according to a predefined protocol, using an electronic form. The strength of evidence was stratified and recommendations were given according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria.

RESULTS

Uncertain evidence deserving further studies was found for two-dose antibiotic prophylaxis for early VAP prevention in comatose patients. In the other cases the risk of resistant-bacteria selection caused by antibiotic administration for 48 hours or more, outweighed potential benefits.

CONCLUSIONS

When accounting for antibiotic-resistant bacteria selection we found no evidence in favour of antibiotic prophylaxis lasting two or more days in the studied clinical conditions.

Year in review 2013: Critical Care--respiratory infections

Infectious complications, particularly in the respiratory tract of critically ill patients, are related to increased mortality. Severe infection is part of a multiple system illness and female patients with severe sepsis have a worse prognosis compared to males. Kallistatin is a protective hormokine released during monocyte activation and low levels in the setting of septic shock can predict adverse outcomes. Presepsin is another biomarker that was recently evaluated and is elevated in patients with severe sepsis patients at risk of dying. The Centers for Disease Control and Prevention has introduced new definitions for identifying patients at risk of ventilator-associated complications (VACs), but several other conditions, such as pulmonary edema and acute respiratory distress syndrome, may cause VACs, and not all patients with VACs may have ventilator-associated pneumonia. New studies have suggested strategies to identify patients at risk for resistant pathogen infection and therapies that optimize efficacy, without the overuse of broad-spectrum therapy in patients with healthcare-associated pneumonia. Innovative strategies using optimized dosing of antimicrobials, maximizing the pharmacokinetic and pharmacodynamic properties of drugs in critically ill patients, and newer routes of drug delivery are being explored to combat drug-resistant pathogens. We summarize the major clinical studies on respiratory infections in critically ill patients published in 2013.

Aspiration pneumonia: a review of modern trends

PURPOSE

The purpose was to describe aspiration pneumonia in the context of other lung infections and aspiration syndromes and to distinguish between the main scenarios commonly implied when the terms aspiration or aspiration pneumonia are used. Finally, we aim to summarize current evidence surrounding the diagnosis, microbiology, treatment, risks, and prevention of aspiration pneumonia.

MATERIALS AND METHODS

Medline was searched from inception to November 2013. All descriptive or experimental studies that added to the understanding of aspiration pneumonia were reviewed. All studies that provided insight into the clinical aspiration syndromes, historical context, diagnosis, microbiology, risk factors, prevention, and treatment were summarized within the text.

RESULTS

Despite the original teaching, aspiration pneumonia is difficult to distinguish from other pneumonia syndromes. The microbiology of pneumonia after a macroaspiration has changed over the last 60 years from an anaerobic infection to one of aerobic and nosocomial bacteria. Successful antibiotic therapy has been achieved with several antibiotics. Various risks for aspiration have been described leading to several proposed preventative measures.

CONCLUSIONS

Aspiration pneumonia is a disease with a distinct pathophysiology. In the modern era, aspiration pneumonia is rarely solely an anaerobic infection. Antibiotic treatment is largely dependent on the clinical scenario. Several measures may help prevent aspiration pneumonia.

Impact of appropriate antimicrobial treatment on transition from ventilator-associated tracheobronchitis to ventilator-associated pneumonia

Introduction

Two small randomized controlled trials have suggested beneficial effects of antibiotic treatment in patients with ventilator-associated tracheobronchitis (VAT). The primary aim of this study is to determine the impact of appropriate antibiotic treatment on transition from VAT to ventilator-associated pneumonia (VAP) in critically ill patients. The secondary objective was to determine the incidence of VAP in patients with VAT.

Methods

This was a prospective observational multicenter study. All patients with a first episode of VAT were eligible. Patients with tracheostomy at intensive care unit (ICU) admission, and those with VAP prior to VAT were excluded. VAT was defined using all the following criteria: fever > 38°C with no other cause, purulent tracheal secretions, positive tracheal aspirate (≥10⁵ cfu/mL), and absence of new infiltrate on chest X ray. Only VAP episodes diagnosed during the 96 h following VAT, and caused by the same bacteria, were taken into account. Antibiotic treatment was at the discretion of attending physicians. Risk factors for transition from VAT to VAP were determined using univariate and multivariate analysis. All variables from univariate analysis with P values <0.1 were incorporated in the multivariate logistic regression analysis.

Results

One thousand seven hundred and ten patients were screened for this study. Eighty-six, and 123 patients were excluded for tracheostomy at ICU admission, and VAP prior to VAT; respectively. One hundred and twenty two (7.1%) patients were included. 17 (13.9%) patients developed a subsequent VAP. The most common microorganisms in VAT patients were Pseudomonas aeruginosa (30%), Staphylococcus aureus (18%), and Acinetobacter baumannii (10%). Seventy-four (60%) patients received antimicrobial treatment, including 58 (47.5%) patients who received appropriate antimicrobial treatment. Appropriate antibiotic treatment was the only factor independently associated with reduced risk for transition from VAT to VAP (OR [95% CI] 0.12[0.02-0.59], P = 0.009). The number of patients with VAT needed to treat to prevent one episode of VAP, or one episode of VAP related to P. aeruginosa was 5, and 34; respectively.

Conclusions

Appropriate antibiotic treatment is independently associated with reduced risk for transition from VAT to VAP.

Introduction to propensity scores

Although randomization provides a gold-standard method of assessing causal relationships, it is not always possible to randomly allocate exposures. Where exposures are not randomized, estimating exposure effects is complicated by confounding. The traditional approach to dealing with confounding is to adjust for measured confounding variables within a regression model for the outcome variable. An alternative approach--propensity scoring--instead fits a regression model to the exposure variable. For a binary exposure, the propensity score is the probability of being exposed, given the measured confounders. These scores can be estimated from the data, for example by fitting a logistic regression model for the exposure including the confounders as explanatory variables and obtaining the estimated propensity scores from the predicted exposure probabilities from this model. These estimated propensity scores can then be used in various ways-matching, stratification, covariate-adjustment or inverse-probability weighting-to obtain estimates of the exposure effect. In this paper, we provide an introduction to propensity score methodology and review its use within respiratory health research. We illustrate propensity score methods by investigating the research question: 'Does personal smoking affect the risk of subsequent asthma?' using data taken from the Tasmanian Longitudinal Health Study.

Guidelines for the prevention of ventilator-associated pneumonia and their implementation. The Spanish "Zero-VAP" bundle

BACKGROUND

"Zero-VAP" is a proposal for the implementation of a simultaneous multimodal intervention in Spanish intensive care units (ICU) consisting of a bundle of ventilator-associated pneumonia (VAP) prevention measures.

METHODS/DESIGN

An initiative of the Spanish Societies of Intensive Care Medicine and of Intensive Care Nurses, the project is supported by the Spanish Ministry of Health, and participation is voluntary. In addition to guidelines for VAP prevention, the "Zero-VAP" Project incorporates an integral patient safety program and continuous online validation of the application of the bundle. For the latter, VAP episodes and participation indices are entered into the web-based Spanish ICU Infection Surveillance Program "ENVIN-HELICS" database, which provides continuous information about local, regional and national VAP incidence rates. Implementation of the guidelines aims at the reduction of VAP to less than 9 episodes per 1000 days of mechanical ventilation. A total of 35 preventive measures were initially selected. A task force of experts used the Grading of Recommendations, Assessment, Development and Evaluation Working Group methodology to generate a list of 7 basic "mandatory" recommendations (education and training in airway management, strict hand hygiene for airway management, cuff pressure control, oral hygiene with chlorhexidine, semi-recumbent positioning, promoting measures that safely avoid or reduce time on ventilator, and discouraging scheduled changes of ventilator circuits, humidifiers and endotracheal tubes) and 3 additional "highly recommended" measures (selective decontamination of the digestive tract, aspiration of subglottic secretions, and a short course of iv antibiotic).

DISCUSSION

We present the Spanish VAP prevention guidelines and describe the methodology used for the selection and implementation of the recommendations and the organizational structure of the project. Compared to conventional guideline documents, the associated safety assurance program, the online data recording and compliance control systems, as well as the existence of a pre-defined objective are the distinct features of "Zero VAP".